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#1
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Cutting fibreglass
Hi,
Just removed the old engine in Far Cove and started rebuilding the stringers. There's much more fibreglass than I expected: about 1/4" all round the wood. And from what I've seen, the wood in in pretty good shape: just some localized rot around where the lag bolts went it. So...what's the Best Way to get the fg top off the stringers? I used an angle-grinder, but there's now fg dust EVERYWHERE. Any hints on keeping the dust mamageable? Run a vacuum cleaner while I'm cutting? Also: I was thinking of just cutting around the sides, and if poly fg sticks as poorly as everyone here says, I could just lift the top off, exposing the wood underneath. No Way! The top is definitely stuck to the wood. So what's the best way to get the top off: cut the sides in, or grind down from the top? It's about 1/4" of fg and gelcoat, and the stringers are about 4" wide. Lloyd Sumpter "Far Cove" Catalina 36 |
#2
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Cutting fibreglass
"Lloyd Sumpter" wrote in message ... Hi, Just removed the old engine in Far Cove and started rebuilding the stringers. There's much more fibreglass than I expected: about 1/4" all round the wood. And from what I've seen, the wood in in pretty good shape: just some localized rot around where the lag bolts went it. So...what's the Best Way to get the fg top off the stringers? I used an angle-grinder, but there's now fg dust EVERYWHERE. Any hints on keeping the dust mamageable? Run a vacuum cleaner while I'm cutting? An angle grinder is usually the best way, but with a thin cut off wheel to cut the laminate, not grind it off. Use a lot of plastic sheeting to make a tent inside the boat to at least contain the dust in as small an area as possible. Take off the cushions and close all locker doors anyway. I doubt running a vacuum while cutting will make a difference. -- Evan Gatehouse you'll have to rewrite my email address to get to me ceilydh AT 3web dot net (fools the spammers) |
#3
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Cutting fibreglass
You might try a new, specialized, 7 1/4 inch, circular electric saw cutting
blade available at Home Depot. I bought one for cutting Hardiplank and it worked very well. I think the circular saw will have to be thrown away when the project is done, due to the cement dust that penetrated everywhere. The blade costs $16.00 and has about 4 or 5 carbide teeth...for the whole blade! Amazingly, it cut Hardiplank like a charm. A little rough around the edges, but who cares in your application? You might want to give it a try. it would be a lot faster than grinding the material away, I'd think. RichG |
#4
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Cutting fibreglass
Try cutting it at about a 25-degree angle across the weave with a
rotary cutter that you can get from a fabric store. The angled cut helps a tremendous amount with the unraveling problem. Tom A. |
#5
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Cutting fibreglass
Lloyd,
You are in for a lot of fun - not. That suggestion that you build a polysheet tent and cover everything that you can't remove is good. Having a vacuum running can collect a lot of the dust. If you can arrange to gring toward the sucker all the better. There are large collectors available for machines - they can help if you can fit it in the work area. Next - Get earplugs, a full face respirator and a box of tyvek suits. You will also need ducktape to attach the gloves so nothing leaks up your arms. If you cut the glass instead of grinding it, you can make more chips and less dust. There are 4-1/2 circular saws available and Porter-Cable (at least, maybe others) makes a 15 or so tooth blade that will saw glass just fine. If you can cut both sides of the engine beds then you could finish the cut through with a reciprocating saw. If you cut the engine beds lower than may be needed, you can always build them back up. Glass on stingers and bed logs will help them rot because the glass cover assures that the water can't get back out. Leave as much wood open as you can. Been there - Done That, bought the T-shirt - it's worn out If I can be of assistance, I'm here a often. You could also decode the secret @ddress. Matt Colie - Been at this too long (see other sigs) Lloyd Sumpter wrote: Hi, Just removed the old engine in Far Cove and started rebuilding the stringers. There's much more fibreglass than I expected: about 1/4" all round the wood. And from what I've seen, the wood in in pretty good shape: just some localized rot around where the lag bolts went it. So...what's the Best Way to get the fg top off the stringers? I used an angle-grinder, but there's now fg dust EVERYWHERE. Any hints on keeping the dust mamageable? Run a vacuum cleaner while I'm cutting? Also: I was thinking of just cutting around the sides, and if poly fg sticks as poorly as everyone here says, I could just lift the top off, exposing the wood underneath. No Way! The top is definitely stuck to the wood. So what's the best way to get the top off: cut the sides in, or grind down from the top? It's about 1/4" of fg and gelcoat, and the stringers are about 4" wide. Lloyd Sumpter "Far Cove" Catalina 36 |
#6
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Cutting fibreglass
Use a diamond wheel in a small grinder.
The diamond will cut the fiberglass like butter. Use a grinder to clean the last bit off the wood. "Lloyd Sumpter" wrote in message ... Hi, Just removed the old engine in Far Cove and started rebuilding the stringers. There's much more fibreglass than I expected: about 1/4" all round the wood. And from what I've seen, the wood in in pretty good shape: just some localized rot around where the lag bolts went it. So...what's the Best Way to get the fg top off the stringers? I used an angle-grinder, but there's now fg dust EVERYWHERE. Any hints on keeping the dust mamageable? Run a vacuum cleaner while I'm cutting? Also: I was thinking of just cutting around the sides, and if poly fg sticks as poorly as everyone here says, I could just lift the top off, exposing the wood underneath. No Way! The top is definitely stuck to the wood. So what's the best way to get the top off: cut the sides in, or grind down from the top? It's about 1/4" of fg and gelcoat, and the stringers are about 4" wide. Lloyd Sumpter "Far Cove" Catalina 36 |
#7
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Cutting fibreglass
If the rot is just around the lag bolt holes, why not cut them out with a
hole saw and fill with epoxy and filler instead of replacing the entire wooden stringer? Merlin "Lloyd Sumpter" wrote in message ... Hi, Just removed the old engine in Far Cove and started rebuilding the stringers. There's much more fibreglass than I expected: about 1/4" all round the wood. And from what I've seen, the wood in in pretty good shape: just some localized rot around where the lag bolts went it. So...what's the Best Way to get the fg top off the stringers? I used an angle-grinder, but there's now fg dust EVERYWHERE. Any hints on keeping the dust mamageable? Run a vacuum cleaner while I'm cutting? Also: I was thinking of just cutting around the sides, and if poly fg sticks as poorly as everyone here says, I could just lift the top off, exposing the wood underneath. No Way! The top is definitely stuck to the wood. So what's the best way to get the top off: cut the sides in, or grind down from the top? It's about 1/4" of fg and gelcoat, and the stringers are about 4" wide. Lloyd Sumpter "Far Cove" Catalina 36 |
#8
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Cutting fibreglass
Merlin may have the right idea: Don't do anything you don't have to.
That said, it just depends on what tools you want to use. A small circ saw with a carbid blade can cut the top corners off the logs freeing the top and the top edges of the sides; if you have an power plane with old blades you don't mind wasting, that will take the corners (or the whole top) off, too. Then you pry remaining glass off with a flat bar. A recip saw with a long flexible blade with a few large teeth can be laid flat against the hull to "flush cut" the bottoms of the sides. Again, a flat bar will take the rest. If you don't like a recip saw, a wide sharp chisel and a hammer will cut the inside bottom corners along the hull - and no dust! Get a diamond sharpening "stone" to put your edge back on the chisel. A chisel can also take the top by cutting straight on the top a 1/4" along inside the sides - then pry up the glass on top a little and use the flat bar. Pry the other way and get the sides free. But if it's built like brick **** and solid as gibralter, why not just use it to build on? If you need to lower a section, use a power plane with the exhaust port hooked to a shop vac to take it down as far as you need; discard the planer blades after. Then disk sand the sides and epoxy more glass over your new top surface. My understand has that it's better to bolt rather than lag the engine mounting (to the logs), if possible. This can often be done by bolting hefty angle channel to the sides of the logs, with the "flat" side up to carry the (bolted on) engine mounts. _Heavy_ mild steel angle works well and will cut and drill easily; it will look better longer if it's preped and painted nicely after drilling, before installation. Clamp solidly in place to mark holes and cuts. If you mark it, most shops will cut and drill for a few bucks a hole. Rufus MMC wrote: If the rot is just around the lag bolt holes, why not cut them out with a hole saw and fill with epoxy and filler instead of replacing the entire wooden stringer? Merlin "Lloyd Sumpter" wrote in message ... Hi, Just removed the old engine in Far Cove and started rebuilding the stringers. [SNIP] |
#9
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Cutting fibreglass
The reason is that I didn't KNOW there was no rot until I took the top off. I've done that now (2hrs prep, 10 mins work with the Trusty angle-grinder and a hatchet), and have confirmed the stringers are fine. I think I'll drill some (3/4"?) holes and punch in dowels coated in epoxy. I feel epoxy would crack if 1/4" lag bolts were screwed into it - better to use wood. Then cover them back up with epoxy/glass and gelcoat. Lloyd Sumpter "Far Cove" Catalina 36 On Sat, 03 Jan 2004 17:11:40 +0000, MMC wrote: If the rot is just around the lag bolt holes, why not cut them out with a hole saw and fill with epoxy and filler instead of replacing the entire wooden stringer? Merlin "Lloyd Sumpter" wrote in message ... Hi, Just removed the old engine in Far Cove and started rebuilding the stringers. There's much more fibreglass than I expected: about 1/4" all round the wood. And from what I've seen, the wood in in pretty good shape: just some localized rot around where the lag bolts went it. So...what's the Best Way to get the fg top off the stringers? I used an angle-grinder, but there's now fg dust EVERYWHERE. Any hints on keeping the dust mamageable? Run a vacuum cleaner while I'm cutting? Also: I was thinking of just cutting around the sides, and if poly fg sticks as poorly as everyone here says, I could just lift the top off, exposing the wood underneath. No Way! The top is definitely stuck to the wood. So what's the best way to get the top off: cut the sides in, or grind down from the top? It's about 1/4" of fg and gelcoat, and the stringers are about 4" wide. Lloyd Sumpter "Far Cove" Catalina 36 |
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